This invention relates to copolymeric materials having dye mordanting capability. More particularly, it relates to copolymeric mordant materials especially suited to application in photographic diffusion transfer products and processes.
Diffusion transfer photographic products and processes have been described in numerous patents, including, for example, U.S. Pat. Nos. 2,983,606; 3,345,163; 3,362,819; 3,594,164; and 3,594,165. In general, diffusion transfer photographic products and processes involve film units having a photosensitive system including at least one silver halide layer usually integrated with an image-providing material, e.g., an image dye-providing material. After photoexposure, the photosensitive system is developed, generally uniformly distributing an aqueous alkaline processing composition over the photoexposed element, to establish an imagewise distribution of a diffusible image-providing material. The image-providing material is selectively transferred, at least in part, by diffusion to an image-receiving layer or element positioned in a superposed relationship with the developed photosensitive element and capable of mordanting or otherwise fixing the image-providing material. The image-receiving layer retains the transferred image for viewing and in some diffusion transfer products, the image is viewed in the layer after separation from the photosensitive element, while in other products, such separation is not required.
Various polymeric materials have been utilized as mordants in photographic products and processes including those of the diffusion transfer type. Thus, polymeric mordants suited to application in diffusion transfer products and processes for the formation of photographic images in dye are described, for example, in U.S. Pat. Nos. 3,148,061 (issued Sep. 8, 1964 to H. C. Haas); 3,758,445 (issued Sep. 11, 1973 to H. L. Cohen, et al. ); 3,770,439 (issued Nov. 6, 1973 to L. D. Taylor); 3,898,088 (issued Aug. 5, 1975 to H. L. Cohen, et al.); 4,080,346 (issued Mar. 31, 1978 to S .F. Bedell); 4,308,335 (issued Dec. 29, 1981 to T. Yamamoto, et al.); 4,322,489 (issued Mar. 30, 1982 to E. H. Land, et al.); 4,563,411 (issued Jan. 7, 1986 to I. Y. Bronstein-Bonte); and 4,794,067 (issued Dec. 27, 1988 to Grasshoff et al.).
The utilization of a particular mordanting material in a photographic product or process will oftentimes depend upon the particular requirements of a photographic product or process and deficiencies or disadvantages associated with the use of a particular mordanting material may be observed. Deficiencies in mordanting capacity, particularly, with respect to one or more dye material desirably utilized, may be noted. Accordingly, the provision of mordanting materials which exhibit favorable maximum density (Dmax) values, is particularly desirable insofar as such properties permit the attainment of desired image formation and quality of photographic reproduction. Desirable mordanting benefits may be realized in some instances by utilizing copolymeric mordant materials obtained, for example, by the polymerization of a polymerizable mordanting compound along with one or more copolymerizable compounds. Examples of copolymeric mordants are disclosed, for example, in the aforementioned U.S. Pat. Nos. 3,770,439; 3,898,088; 4,308,335; 4,322,489; 4,563,411 and 4,794,067. The suitability of a copolymeric mordant will be dictated largely by;the particular monomeric compounds used in the preparation thereof and the particular nature of a photographic system. In addition, difficulties in the synthesis of such copolymeric mordanting materials, and in the production of efficient mordanting materials that can be readily coated into a suitable image-receiving layer, may present formidable limitations upon practical utilization.
It is an object of the present invention to provide polymeric mordant exhibiting efficient dye mordanting capability.
It is another object of the present invention to provide polymeric mordants exhibiting such mordanting capability and adapted to utilization in photographic products and processes.
Still another object of the present invention is the provision of polymeric mordants capable of ready synthesis and efficient utilization in the preparation of coated image-receiving layers containing such polymeric mordants. Other objects of the present invention will become apparent from the description appearing hereinafter.